KR102188596B1 - Radar using array antenna rotation and method for acquiring 3d image thereof - Google Patents

Abstract

The present invention provides an array antenna unit in which a plurality of antennas are arranged, a rotation drive unit that rotates the array antenna unit in a predetermined rotation angle unit parallel to the plane around a predetermined rotation origin in a plane in which the plurality of antennas are arranged, and a predetermined radar specification. According to the rotation angle unit and the rotation angle unit, the maximum number of rotations to rotate the array antenna unit is set, and the antenna control unit that controls the rotation driver according to the set rotation angle unit and the maximum number of rotations, and the array antenna unit for each rotation position of the array antenna unit. A transmission signal of a predetermined waveform is radiated, and a complex weight according to the rotational position of the array antenna is weighted to the received signal received by each of the plurality of antennas, and the synthesized signal strength is displayed for each 3D position to produce a 3D image. It is possible to provide a radar including an acquired signal processor and a method of obtaining a 3D image thereof.

Description

Radar using the rotation of an array antenna and its 3D image acquisition method {RADAR USING ARRAY ANTENNA ROTATION AND METHOD FOR ACQUIRING 3D IMAGE THEREOF}

The present invention relates to a radar and a method of obtaining a 3D image thereof, and to a radar using a rotation of an array antenna and a method of obtaining a 3D image thereof.

The digital beamforming technology is a technology that uses a signal received from a radar channel to synthesize a beam of higher resolution than an actual antenna beam and steers in a desired direction.

In digital beamforming, beam synthesis is performed by multiplying each channel by a complex weight and then adding a signal, and beam steering is performed by changing the complex weight of each channel. Here, the complex weight according to the given beam steering direction is determined by the antenna position of each channel and the wavelength of the center frequency.

At this time, if the distance between the antenna positions of each channel is greater than half of the center frequency wavelength, the angular ambiguity occurs as a signal is largely synthesized at an angle where the target is not actually located. In other words, the location of the target is misunderstood. Therefore, in order to use the digital beamforming technology, the distance between antennas must be narrowed, and for this purpose, the antenna must be designed to be small.

However, if the distance between the antennas is narrowed, the gain of the antenna is reduced, and the radar detection distance is reduced. In addition, since the wavelength of the ultra-high frequency signal is very small, such as in the millimeter wave band, there are cases where it is not possible to design a circuit or hardware with an interval between antennas smaller than half the wavelength. In other words, there is a limit in that a situation in which angle ambiguity cannot be removed occurs.

Korean Patent Publication No. 10-2017-0047773 (published on May 08, 2017)

It is an object of the present invention to provide a radar capable of solving angular ambiguity using rotation of an array antenna even when a plurality of antennas are arranged at intervals of 1/2 or more of a center frequency wavelength, and a method of obtaining a 3D image thereof.

Another object of the present invention is a radar capable of obtaining a 3D image by rotating an array antenna of a radar in parallel with a plane around a predetermined rotation origin in a plane in which a plurality of antennas are arranged to have a required angular resolution, and 3 It is to provide a dimensional image acquisition method.

A radar according to an embodiment of the present invention for achieving the above object includes an array antenna unit in which a plurality of antennas are arranged; A rotation driving unit configured to rotate the array antenna unit in a predetermined rotation angle unit parallel to a plane around a predetermined rotation origin in a plane in which the plurality of antennas are arranged; An antenna control unit configured to set a maximum number of rotations to rotate the array antenna unit in the rotation angle unit and the rotation angle unit according to a predetermined radar specification, and control the rotation driving unit according to the set rotation angle unit and the maximum number of rotations; And radiating a transmission signal of a predetermined waveform through the array antenna unit for each rotational position of the array antenna unit, and adding a complex weight according to the rotation position of the array antenna unit to the received signal received by each of the plurality of antennas to synthesize, A signal processor for obtaining a 3D image by displaying the synthesized signal strength for each 3D position; Includes.

을 만족하도록 설정할 수 있다.The antenna control unit checks the wavelength (λ) of the center frequency of the radar, the required beam width (θ _3dB ) and angular resolution (δθ _3dB ), and the arrangement structure of a plurality of channels according to the arrangement of the plurality of antennas, and the rotation Equation of the rotation angle unit (Δα) according to the maximum phase center distance (a _l,max ) and the beam width (θ _3dB ), which is the phase center distance of the channel at the farthest distance from the origin and the rotation origin.

Can be set to satisfy.

를 만족하도록 설정할 수 있다.The antenna control unit calculates the maximum number of rotations (M) when the phase centers of the plurality of channels of the array antenna unit are arranged in an n-th rotational symmetry around the rotation origin.

Can be set to satisfy

에 따라 획득할 수 있다.The signal processing unit is obtained by compressing the number of samples sampled within the azimuth ( φ ) and elevation angle (θ) range, the azimuth ( φ ) and elevation angle (θ) range specified in the radar (N _φ , N _θ ), and distance compression. which determine the distance information number (n _{r), and, n φ × n θ × n} r of the three-dimensional position in the rectangular coordinates _{(n φ, n θ, n} r) by the signal strength _{(s (n φ, n θ} , n _r ))

Can be obtained according to.

을 만족하도록 제어할 수 있다.When the antenna control unit can adjust the position of the rotation origin at which the rotation driver rotates the array antenna unit, the maximum phase center distance (a _l,max ) is Equation

Can be controlled to satisfy.

The array antenna unit may have a spacing between the plurality of antennas exceeding 1/2 of the center frequency wavelength λ.

A method for obtaining a 3D image of a radar according to another embodiment of the present invention for achieving the above object includes an array antenna in which a plurality of antennas are arranged according to a known radar specification, and a predetermined rotation origin on a plane in which the plurality of antennas are arranged. Setting a rotation angle unit to be rotated around and a maximum number of rotations to rotate the array antenna in the rotation angle unit; Rotating the array antenna parallel to a plane in which a plurality of antennas are arranged in units of a set rotation angle; Transmitting and emitting radiation for each rotational position of the array antenna, and obtaining a received signal received through each of the plurality of antennas; Synthesizing the received signal by weighting a complex weight according to a rotation position of the array antenna; And obtaining a 3D image by displaying the synthesized signal strength for each 3D position. Includes.

Therefore, in the radar and its 3D image acquisition method according to an embodiment of the present invention, the array antenna of the radar rotates parallel to the plane around a predetermined rotation origin in a plane in which a plurality of antennas are arranged to have a required angular resolution. Even if multiple antennas of the array antenna are arranged at intervals of 1/2 or more of the center frequency wavelength, angular ambiguity can be resolved. In addition, while rotating the array antenna, a 3D image of a target may be obtained using received signals received in various steering directions.

1 shows a schematic configuration of a radar according to an embodiment of the present invention.
2 is a diagram illustrating a phase center and beamforming of an array antenna.
3 is a diagram illustrating a comparison between a conventional radar and a 3D image acquired from a radar according to the present embodiment for a single target.
4 shows a 3D image obtained by a radar according to the present embodiment for a plurality of targets.
5 shows a method of obtaining a 3D image by a radar according to an embodiment of the present invention.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the implementation of the present invention, reference should be made to the accompanying drawings illustrating preferred embodiments of the present invention and the contents described in the accompanying drawings.

Hereinafter, the present invention will be described in detail by describing a preferred embodiment of the present invention with reference to the accompanying drawings. However, the present invention may be implemented in various different forms, and is not limited to the described embodiments. In addition, in order to clearly describe the present invention, parts irrelevant to the description are omitted, and the same reference numerals in the drawings indicate the same members.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components unless specifically stated to the contrary. In addition, terms such as "... unit", "... group", "module", and "block" described in the specification mean units that process at least one function or operation, which is hardware, software, or hardware. And software.

1 shows a schematic configuration of a radar according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating a phase center and beamforming of an array antenna.

Referring to FIG. 1, the radar according to the present embodiment includes an array antenna unit 110, a rotation driving unit 120, an antenna control unit 130, and a signal processing unit 140.

The array antenna unit 110 includes a plurality of antennas that are arranged at a predetermined position on the same plane to transmit and receive signals. In this embodiment, it is assumed that a plurality of antennas are disposed on the xy plane, and each of the plurality of antennas is steered in the z-axis direction perpendicular to the xy plane. Here, the number and arrangement form of antennas provided in the array antenna unit 110 can be variously adjusted, and the distance between adjacent antennas in the plurality of antennas is 1/ of the center frequency wavelength (λ) of the signal operated by the radar. It can be 2 or more. In addition, each of the plurality of antennas of the array antenna unit 110 may be a transmission/reception antenna for transmitting and receiving signals, but some may function as a transmission antenna, and the others may be configured to function as a reception antenna.

The radar according to the present embodiment can be used as a single channel radar or a multi-channel radar in which coherency between pulses is maintained, and when used as a multi-channel radar, there is no phase difference between channels or the phase difference is measured and corrected. can do.

If the radar uses multiple channels and the antenna performing transmission and the antenna performing reception are the same in the array antenna unit 110, the phase center of the antenna corresponding to each channel (c _l ) is each channel Becomes the phase center of As an example, when each of the plurality of antennas operates as an individual channel (c _l ) for transmitting and receiving, the phase center of each of the plurality of antennas becomes the phase center (P ₁ ) of each corresponding channel (c _l ). However, when the transmit antenna and the receive antenna are different from each other, the midpoint between the transmit antenna and the receive antenna becomes the phase center (P _l ) of the corresponding channel (c _l ).

Meanwhile, in the present embodiment, a signal is transmitted while rotating the array antenna unit 110 on which a plurality of antennas are disposed on an xy plane, and a 3D image of the target is obtained by receiving a signal reflected from the target. At this time, the rotation center of the array antenna unit 110 is referred to as a rotation origin (O). And as shown in FIG. 2, when the coordinates of the rotation origin (O) are (0, 0), the phase center of the l-th channel (c _l ) among _L channels (c ₀ ~ c _L-1 ) ( coordinates (d _x, d _y) is the phase center (P _l) of the phase center (P _l) the distance (a _l) and the x-axis and the l-th channel (c _l) to from the rotation reference point (O) of P _l) This can be expressed in the form of the spherical coordinate system of the angle α _l .

Here, l of the second channel (c _l) rotating the phase center (P _l) l channel the distance to from the origin (O) (c _l) phase-to-center distance (a _l) la and, l-th channel (c _l) of the The angle formed by the phase center (P _l ) with the x-axis is referred to as the phase center angle (α _l ) of the l channel (c _l ).

The rotation driving unit 120 is coupled to the array antenna unit 110 and rotates the array antenna unit 110 on the xy plane around a designated rotation origin O under the control of the antenna control unit 130. That is, the rotation driving unit 120 rotates the array antenna unit 110 about the z-axis.

In this embodiment, when the rotation driving unit 120 rotates the array antenna unit 110, even if the distance between the plurality of antennas is equal to or greater than 1/2 of the center frequency wavelength λ, angular ambiguity is excluded and the required gain is applied to the target. It is to be able to acquire a 3D image of the image.

In order to obtain a three-dimensional image of the target p, the antenna control unit 130 is assigned a rotation angle unit (Δα) designated by the signal processing unit 140 according to the requirements of the radar. The rotation driving unit 120 is controlled to rotate the number of times (M).

The antenna control unit 130 includes a position of a rotation origin (O), which is a reference point for rotating the array antenna unit 110, and a rotation angle unit (Δα) for rotating the array antenna unit 110, and maximum rotation according to specifications required for the radar. Determine the number of times (M). And by transmitting the determined rotation origin (O), rotation angle unit (Δα) and maximum number of rotations (M) to the antenna control unit 130, the array antenna unit 110 rotates around the rotation origin (O). The rotation driving unit 120 is controlled to rotate up to M times by Δα).

In this embodiment, the antenna control unit 130 first determines the position of the rotation origin (O(0, 0)) according to the angular resolution required by the radar. That is, the coupling position of the array antenna unit 110 and the rotation driving unit 120 is determined. When the required 3dB beam width (θ _3dB ) along with the wavelength (λ) of the center frequency is determined in advance, the antenna control unit 130 is based on the angular resolution (δθ _3dB ), and a plurality of channels (c ₀ ~) from the rotation origin (O) The position of the rotation origin (O(0, 0)) is determined so that the phase center distance (a _l,max ) of the channel (c _l ) at the farthest distance among c _L-1 ) satisfies Equation 1.

In the digital beam fobbing technique, the wider the multiple antennas of the array antenna unit 110 are distributed, the narrower the beam width, so that a smaller angular resolution can be obtained. In order to obtain the angular resolution for the channel having the maximum phase center distance (a _l,max ), the rotation angle unit (Δα) is set to a value that infinitely converges to 0, and the array antenna unit 110 rotates 360 degrees. Assuming that, the maximum number of rotations (M) is calculated as M = 2π/Δα. Accordingly, the magnitude distribution function (s(φ, θ)) for the signal intensity different from the steering direction of the 3D image acquired by the signal processing unit 140 is determined according to a type 1 Bessel function (J ₀ (·)). It is obtained by Equation 2.

0.5로 알려져 있으므로, 최대 위상 중심 거리(a_l,max)는 수학식 1에 따라 결정될 수 있다.And in the first kind Bessel function (J ₀ (·)), J ₀ (1.1226)

Since it is known as 0.5, the maximum phase center distance a _l,max can be determined according to Equation 1.

However, the position of the rotation origin (O(0,0)) is determined according to the coupling position of the array antenna unit 110 and the rotation driving unit 120, and generally, the position of the array antenna unit 110 and the rotation driving unit 120 The bonding position is not easy to change. That is, in most cases, the position of the rotation origin (O(0,0)) cannot be arbitrarily changed. Therefore, the position of the rotation origin (O(0,0)) is determined in advance according to the coupling position of the array antenna unit 110 and the rotation driver 120, and the maximum phase center distance (a _l,max ) is the rotation origin (O It can be obtained by measuring the phase center distance of the channel c _l of the farthest distance based on (0,0)).

When the maximum phase center distance (a _l,max ) is obtained, the antenna control unit 130 determines the rotation angle unit (Δα) using the obtained maximum phase center distance (a _l,max ) and 3dB beam width (θ _3dB ). do.

The target p located at the azimuth angle φ _p and the elevation angle θ _p in the spherical coordinate system has a phase according to Equation 3 when the l-th channel c ₁ rotates by the rotation angle α.

In Equation 3, the instantaneous frequency of the signal with respect to the rotation angle α may be calculated according to Equation 4.

Equation 4 must satisfy Equation 5, which becomes the bandwidth of the signal with respect to the rotation angle α of the array antenna unit 110.

According to the Nyquist-Shannon sampling theorem, the rotation angle unit (Δα), which is the sampling interval of the rotation angle α capable of completely recovering a signal, must satisfy Equation 6.

Combining Equation 5 and Equation 6, it can be seen that the rotation angle unit Δα should be determined to satisfy Equation 7.

That is, the antenna control unit 130 may determine the rotation angle unit Δα to satisfy Equation 7.

On the other hand, when the rotation angle unit (Δα) is determined according to Equation 7, the antenna control unit 130 includes a rotation angle unit (Δα) and a plurality of channels (c ₁ to c _L-1 ) of the array antenna unit 110. The maximum number of rotations (M) is determined according to the arrangement structure.

When the phase center P _l of the plurality of channels c ₁ to c _L-1 of the array antenna unit 110 is disposed in an n-th rotational symmetry around the rotation origin O, the antenna control unit 130 The maximum number of rotations (M) is determined according to Equation 8.

When a plurality of channels (c ₁ ~ c _L-1 ) rotate n times in rotation angle unit (Δα) and have the same arrangement structure as before rotation, it is necessary to rotate the array antenna unit 110 by 360 degrees. none. For example, as shown in FIG. 2, when a plurality of channels (c ₁ to c _L-1 ) are 4th order (n = 4) rotationally symmetric, the array antenna unit 110 is only in the range of 0 to 90° Just rotate. This is because the same signal is obtained in the remaining 90° to 360° rotation range. Therefore, when the rotation angle unit Δα is 10°, for example, the array antenna unit 110 may determine the maximum number of rotations M as 9 according to Equation 10.

The signal processing unit 140 generates a transmission signal of a predetermined waveform and transmits it to a plurality of antennas of the array antenna unit 110 so that the plurality of antennas radiate the transmission signal. Here, the transmission signal may be a pulse file as an example, but is not limited thereto. In addition, the signal processing unit 140 receives and analyzes the received signals reflected from the target p and received by a plurality of antennas, and generates a 3D image of the target.

When the number of channels is L, the signal processing unit 140 compresses the signals of each of the _L channels (c ₁ to c _L-1 ) by distance and reflects the received signal according to the distance from each channel to indicate the energy distribution of the received signal. L range profiles can be obtained.

And the complex weight (wc) according to Equation 9 is multiplied and summed according to the arrangement position (d _x , d _y ) of each channel (c _l ) corresponding to each of the L distance profiles, so that the signal is the origin (O(0, 0) )) can be steered to be directed to the azimuth (φ) and elevation angle (θ).

Here, λ represents the wavelength of the center frequency of the signal operated by the radar of the signal.

That is, the distance in the x-axis direction (d _x ) and the y-axis direction (d _y ) and steering of a number of channels based on the origin (O(0, 0)) in multiple distance profiles obtained by distance compression of the received signal. By multiplying the complex weights wc according to the directions (φ, θ) and then adding them all, the beamforming is performed in the steering directions (φ, θ).

When there is a target in the direction (φ, θ) steered by beamforming, the intensity of the synthesized signal increases relatively, whereas when there is no target in the steered direction (φ, θ), the intensity of the synthesized signal is It becomes relatively small.

However, in the radar according to the present embodiment, the array antenna unit 110 may rotate on the xy plane with respect to the z-axis by the rotation driving unit 120. In particular, beamforming is performed while rotating the array antenna unit 110 the number of times M designated by the rotation angle unit (Δα). Accordingly, the signal processing unit 140 may obtain the complex weight wc of Equation 9 by transforming it into a spherical coordinate system format as shown in Equation 10 so that beamforming is performed at all rotation angles at which the array antenna unit 110 rotates.

(Here, m represents the number of rotations of the array antenna unit 110 that rotates in units of rotation angle (Δα).)

The signal processing unit 140 range-compresses signals received through each of the _L channels (c ₁ to c _L-1 ) while the array antenna unit 110 rotates M times to position N _r distance information. Digital data in the form of a complex number having a magnitude and a phase for each (range bin) is obtained as a range profile. That is, the signal processing unit 140 acquires M × L distance profiles s(m, l, n _r ).

In addition, the signal processing unit 140 multiplies and sums the complex weight wc of Equation 10 for each of the obtained M × L distance profiles s(m, l, n _r )) to perform digital beamforming.

The radar must be able to search for targets in a predetermined range of azimuth ( φ ) and elevation angle (θ). Here, as an example, the radar's azimuth ( φ ) is adjusted in the range of 0 to 360°, and the elevation angle (θ) is It assumed to be required to be adjusted in the field of view _{(Field of View) (θ FOV} ) range _{(-θ FOV / 2 ~ θ FOV} / 2). If the number of azimuth angles ( φ ) and elevation angles (θ) sampled in the specified range is N _φ and N _θ , respectively, the radar is measured at N _φ × N _θ × N _r 3D spherical coordinates with the number of distance information positions. The signal strength for each position (n _φ , n _θ , n _r ) may be obtained according to Equation 11.

As described above, when a target exists in the direction (φ, θ) steered by beamforming, the synthesized signal appears with a relatively high intensity, whereas when there is no target in the steered direction (φ, θ), Since the intensity of the synthesized signal is relatively small, the signal processing unit 140 visually displays the signal intensity for each position (n _φ , n _θ , n _r ) obtained according to Equation 11 to provide a 3D image of the target. Can be obtained.

3 is a diagram showing a comparison of a 3D image obtained from a radar according to the present exemplary embodiment with a conventional radar for a single target, and FIG. 4 is a diagram illustrating a 3D image obtained from a radar according to the exemplary embodiment for a plurality of targets. Show.

Referring to (a) in FIG. 3, in a conventional radar that does not rotate the array antenna unit 110, the distance between the antennas is arranged at an interval of 1/2 (λ/2) or more of the center frequency wavelength, so that multiple single targets The angle ambiguity detected at different locations of On the other hand, the radar according to the present embodiment shown in (b) performs digital beamforming while rotating the array antenna unit 110 to remove angular ambiguity, so that the three-dimensional position of a single target can be accurately detected.

4 shows a 3D image when the radar detects 3D positions for 5 targets. As shown in FIG. 4, the radar according to the present exemplary embodiment can generate a 3D image by accurately detecting 3D positions for a plurality of targets as well as a single target.

5 shows a method of obtaining a 3D image by a radar according to an embodiment of the present invention.

Referring to FIGS. 1 to 4, a method of acquiring a 3D image of the radar of FIG. 5 will be described. First, the specifications of the radar are checked (S11). Here, radar specifications include the number of samples sampled within the range of the wavelength (λ) and azimuth ( φ ) and elevation angle (θ) of the center frequency, azimuth ( φ ) and elevation angle (θ) (N _φ , N _θ ), and distance. Check the number of distance information (N _r ) obtained by compression. In addition, the beam width (θ _3dB ) and the angular resolution (δθ _3dB ) may be included. In particular, the arrangement structure of the plurality of channels c ₁ to c _{L-1 in} the array antenna unit 110 including a plurality of antennas is checked.

When the specifications of the radar are confirmed, a rotation angle unit (Δα) for rotating the array antenna unit 110 is set. The rotation angle unit (Δα) is the maximum phase center distance (a), which is the phase center distance between the rotation origin (O(0, 0)) of the rotating array antenna unit 110 and the channel (c _l ) farthest from the rotation origin. _It is set to satisfy Equation 7 using _l,max ) and a 3dB beamwidth (θ _3dB ).

At this time, if the position of the rotation origin (O(0, 0)) of the array antenna unit 110 is adjustable, the rotation origin (O(0, 0)) is the maximum phase center distance (a _l,max ). It can be set in advance to satisfy Equation 1.

On the other hand, when the rotation angle unit Δα is set, the maximum number of rotations M is determined according to Equation 8 according to the arrangement structure of the plurality of channels c ₁ to c _L-1 .

In addition, the radar transmits a transmission signal while rotating up to M times in a rotation angle unit (Δα) from the initial position of the array antenna unit 110, and receives a reflected signal to measure the intensity and phase of the signal. The radar first transmits a transmission signal at a predetermined initial position and receives the reflected reception signal to obtain a distance profile (S14). At this time, the received signals received through each of the plurality of (L) channels (c ₁ ~ c _L-1 ) at each rotation angle are distance-compressed to form a complex number having a size and phase for each of N _r distance information range bins. Digital data of can be obtained as a distance profile. That is, M × L distance profiles s(m, l, n _r )) for each rotational position of the array antenna unit 110 are obtained.

And it is determined whether the number of rotations (m) of the current array antenna unit 110 is equal to or greater than the set maximum number of rotations (M) (S15). If the current number of rotations (m) is less than the maximum number of rotations (M), the array antenna unit 110 is rotated by a rotation angle unit (Δα) (S16). Then, a transmission signal is transmitted again at a position in which the array antenna is rotated, and a reflected signal is received to obtain a distance profile (S14). However, if the current number of rotations (m) is greater than or equal to the maximum number of rotations (M), the complex weight of Equation 10 as shown in Equation 11 for the obtained M × L distance profiles (s(m, l, n _r )) ( By multiplying and adding wc), digital beamforming is performed to obtain complex data representing the signal strength for each 3D position (S17). In addition, a 3D image of the target is obtained by visually displaying the signal strength for each position (n _φ , n _θ , n _r ) obtained according to Equation 11 (S18).

The angular ambiguity can be eliminated even if a plurality of antennas of the array antenna are arranged at intervals of 1/2 or more of the center frequency wavelength by rotating the center of the phase so that the radar array antenna has the required angular resolution. In addition, while rotating the array antenna, a 3D image of a target may be obtained using received signals received in various steering directions.

The method according to the present invention may be implemented as a computer program stored in a medium for execution on a computer. Here, the computer-readable medium may be any available medium that can be accessed by a computer, and may also include all computer storage media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data, and ROM (Read Dedicated memory), RAM (random access memory), CD (compact disk)-ROM, DVD (digital video disk)-ROM, magnetic tape, floppy disk, optical data storage device, and the like.

The present invention has been described with reference to the embodiments shown in the drawings, but these are merely exemplary, and those of ordinary skill in the art will appreciate that various modifications and other equivalent embodiments are possible therefrom.

Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims.

110: array antenna unit 120: rotation driving unit
130: antenna control unit 140: signal processing unit

Claims (10)

An array antenna unit in which a plurality of antennas are arranged;
A rotation driving unit configured to rotate the array antenna unit in a predetermined rotation angle unit parallel to a plane around a predetermined rotation origin in a plane in which the plurality of antennas are arranged;
An antenna control unit configured to set a maximum number of rotations to rotate the array antenna unit in the rotation angle unit and the rotation angle unit according to a predetermined radar specification, and control the rotation driving unit according to the set rotation angle unit and the maximum number of rotations; And
A transmission signal of a predetermined waveform is radiated through the array antenna unit for each rotation position of the array antenna unit, and a complex weight according to the rotation position of the array antenna unit is weighted and synthesized to the received signal received by each of the plurality of antennas, and 3 A signal processor configured to obtain a 3D image by displaying the synthesized signal strength for each dimensional position; Including,
The antenna control unit
Confirm the arrangement structure of the plurality of channels according to the wavelength (λ) of the center frequency of the radar and the required beam width (θ _3dB ) and angular resolution (δθ _3dB ) and the array of the plurality of antennas,
The rotation angle unit (Δα) is calculated according to the maximum phase center distance (a _l,max ) and the beam width (θ _3dB ), which are the phase center distances of the channel at the farthest distance from the rotation origin and the rotation origin.

Radar to set to satisfy.
delete The method of claim 1, wherein the antenna control unit
When the phase centers of the plurality of channels of the array antenna unit are arranged in n-th rotational symmetry around the rotation origin, the maximum number of rotations (M)

Radar to set to satisfy. The method of claim 3, wherein the signal processing unit
Range azimuth (φ) and elevation angle (θ) assigned to the radar, the azimuth angle (φ) and elevation angle (θ) range in number of samples to be sampled from the (N _φ, N _θ), the distance information, the number obtained by the distance compression Check (N _r ), and signal strength for each position (n _φ , n _θ , n _r ) in N _φ × N _θ × N _r three-dimensional spherical coordinates (s(n _φ , n _θ , n _r )) Equation

Radar acquired according to. The method of claim 1, wherein the antenna control unit
If the rotation driving unit can adjust the position of the rotation origin for rotating the array antenna unit, the maximum phase center distance (a _l,max ) is Equation

Radar to control to satisfy. The method of claim 1, wherein the array antenna unit
A radar in which the spacing between the plurality of antennas exceeds 1/2 of the center frequency wavelength λ. The array antenna in which a plurality of antennas are arranged according to a predetermined radar specification is rotated around a predetermined rotation origin on a plane in which the plurality of antennas are arranged, and the maximum rotation to rotate the array antenna in the rotation angle unit. Setting the number of times;
Rotating the array antenna parallel to a plane in which a plurality of antennas are arranged in units of a set rotation angle;
Transmitting and emitting radiation for each rotational position of the array antenna, and obtaining a received signal received through each of the plurality of antennas;
Synthesizing the received signal by weighting a complex weight according to a rotation position of the array antenna; And
Obtaining a 3D image by displaying the synthesized signal strength for each 3D position; Including,
The step of setting the number of rotations
Confirming the arrangement structure of the plurality of channels according to the wavelength (λ) of the center frequency of the radar, the required beam width (θ _3dB ) and angular resolution (δθ _3dB ), and the arrangement of the plurality of antennas; And
The rotation angle unit (Δα) is calculated according to the maximum phase center distance (a _l,max ) and the beam width (θ _3dB ), which are the phase center distances of the channel at the farthest distance from the rotation origin and the rotation origin.

Setting to satisfy; Radar 3D image acquisition method comprising a.

delete The method of claim 7, wherein the setting of the number of rotations comprises:
When the phase centers of the plurality of channels of the array antenna are arranged in n-th rotational symmetry around the rotation origin, the maximum number of rotations (M) is expressed as

Setting to satisfy; Radar 3D image acquisition method further comprising a. The method of claim 9, wherein the synthesizing step
Range azimuth (φ) and elevation angle (θ) assigned to the radar, the azimuth angle (φ) and elevation angle (θ) range in number of samples to be sampled from the (N _φ, N _θ), the distance information, the number obtained by the distance compression Identifying (N _r );
Equation of the signal strength (s(n _φ , n _θ , n _r )) for each location (n _φ , n _θ , n _r ) in N _φ × N _θ × N _r three-dimensional spherical coordinates

Obtaining according to; Radar 3D image acquisition method comprising a.

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